Electric switch



July 28, 1931. B, E, GETCHELL 1,816,429

ELECTRIC SWITCH Filed Sept. 22, 1927 5 Sheets-Sheet 1 INVENTOR21 i1 :1x' 51,51 Benjamin E. Ge 011811, Q

n'. r I RNEY July 28, B E, GETCHELL 1,816,429

ELECTRIC SWITCH Filed Sept. 22, 1927 5 SheelZS-Shee\`l 2 Lig; 3-

INVENTOR Benjamin E. Ge chell,

`uly 28, 1931. B, E. GETCHELL 1,816,429

V ELECTRIC SWITCH Filed sept. 22. 1927 l 5 sheets-sheet s l MINIMUM' .m

llill v.Ilm

July 28, 1931. B. E. GETCHELL 1,815,429

ELECTRIC SWITCH INVENTOR. Benjamin E. G tchell,

July 28,' 1931. B. E. GETCHELL 1,815,429

I ELECTRIC SWITCH Filed Sept. 22. 1927 5 Sheets-Sheet 5 LOAD L IN EINVENTOR Patented [July 2a,l 1931'v UNITED- STATES Pa'rnrrl OFI-icaBENJAMIN E. GETCHELIAOF PLAINVILLE, CONNECTICUT, ASSIGNOB TO THE TRUM-BULL `ELECTRIC MANUFACTURING COMPANYQOF PLAINVILLE, CONNECTICUT, A

1 CORPORATION or CONNECTICUT One object of my invention is to provideanextremely compact and eiicient double break switch of the remote controltype.

switch' of the magnetically controlled type in which the Vcircuit iscarried through the switch without `the'necessity of flexible leads.

Another object is to provide aV double break 'switch in which themovable contact mem- A mpbers are freely removable'for inspection orreplacement without the use of'tools of any description. l' p Anotherobj ect is to provide ya double break switch having a movable contactmember for simultaneously engaging its corresponding stationary contactsand in which the respective contact ends are flexible with respect toeach other and independently self-adjustable with respect to thestationary contacts.

Another Object is to provide a remote c ontrol switch in which all ofthe line and load wire connecting means are positioned on, one level onthe base and all of the remote control wire connecting meansarepositioned on 25 another level in order to facilitate wiring or toidentify the circuits.

Another object is to provide an electric switch having a slotted baseanda series of pairs of stationary contacts together with a a0 .movableinsulating contact-carrying bar positioned between the two members ofeach pair of stationary contacts and having insulating angesco-operating with the slots in thebase to electrically separate the reg5spective pairs of stationary contacts as well as the respective movablecontacts. Another object isF to provide an electric switch constructionincluding a molded insulating bar having insulating barriers and havingcontact positioning studs and movement guiding Y lplates, molded `in thematerial ofthe `bar to form a unit. i

A Another object is to provide an insulating barof the precedingdescriptionand having an independent circuit connecting strip molded inthe material of the bar. l

Another object is to provide aunitary car-` rier for all the movablecontactspof a remotecontrolled switch.

n A further, and an important `object is to- Application med september22, v19a?. serial No. 221,215.

p utilized Another object is to provide a double break ELECTRIC`stv-Irren i provide a switch construction of the remote control t pe inwhich a single magnet is (y1) 'to close the load circuit in response tothe mowement of a co-operating push button, (2) to retain the switch inclosed position under normal load conditions, (3) toopen the loadcircuit in response to the movement of a second push button and (4) toautomatically open the circuit in response to overload conditions. -Itis designed par! 6L ticularly for the use of standard relays which areincluded in the circuit and by the use of 'which itis possible toaccurately fix or to -vary the-exact point at which the switch will beautomatically operated on overload con- 6g ditions. 4

An important object is to provide a constructionin which the movableswitch conv tactsare connected to the movable member e ofanelectro-magnet so as to move simultane- 7g ously with the magnetmember andfor a proportionate 'relative distance as required.-

i Another object is to provide aconstruction in which the movable switchcontacts and the movable member of an electro-magnet are so connected asto -move simultaneously and so that the switch contacts may be moved atany desired angle relative to the lineal path of movement of the magnetmember.

` A particular object of my invention is to 'provide a construction inwhich the movable contacts of a switch are so connected with the movablemember of an electro-magnet that the movement of the magnet member lwill simultaneously move the switch contact 35 at an angle relative tothe corresponding stationary contact so as to engage the latter with anangular or wiping-movement.

Another object is to provide a construction in which the movablecontacts of a switch, or

a similar construction, are connected with the movable member of anelectro-magnet so as to move simultaneously with the magnet member andtofurther provide a guiding means whereby the switch contacts will bemoved in a predetermined angularv path of movement with respect to thelineal movement ofthe magnet member. l This inventionappliesparticularly tothe class of electric switches and similar devices190 rapidly and stops with considerable impact'y against the magnet orsome part of the construction provided for that purpose. Suchconstructions usually include a considerable number of screws ferholding the parts in position in addition to the usual screws forconnecting the circuit wires and the repeated stopping impactof themagnetically operated member against any part of the construction tendsto loosen the parts, especially the screws and it is my particularobject to guard against such danger by providing a construction whichwill allow for the full and complete movement of the magneticallyoperated parts in such a manner that the operating impact will not betransmitted to the screws or other co-related parts.

In the specific form shown herein, the armature is arranged to `be movedto edect the desired result although in some cases it may be desirableto provide a movable magnet coil to co-operate with a relativelystationary armature but, in either case, it is my purpose to provide fora certain relative movement between the magnet and its cooperatingarmature.

In reducing my invention to actual practice, I preferably provide anelectro-magnet (together with its core and pole pieces as a unit) with aform of mounting which .will permit a limited free movement and acooperating-movable armature which has an operableconnection withmovable switch contacts or other parts which are to be operated.

The magnet unit, the armature and the switch contacts are so co-relatedthat, when the armature is attracted by the magnet it will cause asimultaneous movement ofthe switch contacts and, when the armaturestrikes against the poles of the magnet unit, the free movement mountingof the latter will permit it to move in response to the impactbut, dueto this free movement mounting, no shock or impact will be transmittedtothe screws or other parts of the construction.

In other words, the operating shock of the armature will be absorbed bythe magnet unit because of its free movement mounting.

After receiving the operating impact of the armature, the magnet isreturned to its normal on position by the pressure ofthe contact springsand gravity.

' The foregoing describes the basic ideas of the invention, but inpractice, certain refineterasse ments of detail are desirable; forinstance, it is desirable that some ofthe shock of the fast movingarmature be cushioned or abn sorbed by a suitable yielding means beforethe armature actually strikes against the poles of the magnet and it isalso desirable that the switch contacts close with a yielding pressure.These two requirements are provided for by using spring contacts whiche11- gage the corresponding stationary contacts before the armaturereaches the poles or" the magnet and, for the reason that the springcontacts are connected with the armature, the closing impact of thelatter is checked.

When the armature has completed its switch closing movement, it restsagainst the pole pieces of the magnetiand will remain in that positionagainst the tension of the spring contacts which however will operate tocause a rapid se aration of the armature from the magnet w en thecircuit is broken. rlhese spring contacts also operate to move themagnet back into its normal position as it stoodbefore being struck bythe moving Fig. 4 is a rear view, some of the parts bel ing shown insection. f

- Fig. 5 is a view from the right hand side, the right hand side platebeing omitted and parts being shown in section.

Fig. 6 is a vertical sectional view on the plane of the line 6 6 ofFig. 1. t

Fig. 7 is a vertical sectional v1ew on the plane of the line 7 7` ofFig. 1.

Fig. 8 is an exploded perspective view of the contact members anddetails of one of the v switch units.

Fig. 9 is an inverted horizontal sectional i view and plan on theplaneof the line 9 9 of Fig. 1.

Fig. 10 is a perspective view of the insulating base which carries `allof the conducting 'parts except the magnet. v

Fig. l1 is a perspective view of the insulating contact carrying crossbar. Fig. 12 is a diagrammatic view of parts of the switch in anoperating circuit.

The base or body 15 may be formed of in'- sulating material, such asmolded composition. In the form shown the side plates 16 and 17 are ofmetal and provided with flanges which are secured to the base by screws,such as 18 and 19. rlhe back plate 20 may be secured tothe side platesby screws such as 21. This particular form ofside plate is adapted 'forconvenient attachment to a back board or in a switch box (not shown).For conveniencel this back plate is provided with a keyhole fslot 22 atthe top by means of which it may be conveniently hung on a screw (notshown). The lower corners of this Aplate 20 are provided with notches 23and 24 which open toward one side and toward the bottom for conveniencein mounting the plate under theheadsfof screws (not s own) in anenclosing box. v

The line terminals 25, 26 and 27 are mounted on the front face of thebase along itsY lower edge. The load terminals 28, 29 and 30 are mountedin the same plane along the upper edge of the base.` The terminals 31,32 and 33 adaptedrto be connecte-d to a control station or switch aremounted along the upper edge of the base at its rear. The load may be,for instance,/aI motor (not shown).

i vThe switchhas three circuit controlling The units in theparticular'form shown.

left hand unit has stationary contacts 35` and 36and a movable switchmember composed of contact members 37 and 38 connected together by aflexible strip 39 which may be formed of thinlaminations so that the twocontact members 37 `and 38 are free to tilt and rock so as to assureperfect contact with the raised portions 40 and 41 of the vstationarycontacts. The details of this construction are shown particularly inFig. 8.

The back plate .42 hasl its endsk offset from the plane of its centralportion 43 and is provided with small bosses 44 adapted to rest againstthe yback of th'e'connecting strip 39 so as to permit relative tiltingof the contact pieces 37 and 38. The movable contact 'parts justdescribed and the corresponding movable contacts for the `other switchunits yare all carried by the insulating member 45 which extends acrossthe base of the switch in tle form of a Cross bar. This cross bar hasset in it a flat stud 46, the end of which extendsfthrough slots 47 and48 Fig. 8) and lsupports a spring 49 and a cup-like washer 50. Thiswasher has a central slot 51 to permit it to be slipped on to the end ofthe stud 46.' It also has notches 52 adapted to receive the ends of theT-shapedhead 53 of the stud when the washer 50. is rotated land turningJit with the fingers.

The upper contact35 of the leftihand switch unit is electrically andmechanically secured to the terminal l28 by a screw 54.

I The lower contact 36 is secured to the clip 55 for the relay.56 (Fig.12).` The ldwer clip 57 for the relay is electrically and mechanicallyconnected to the lower terminal 25 by screw 58 which may be seated inasuitable-insert in the base inany suitable manner. The intermediateclip K59 for the relay is similarly secured 'to the base.

The right lhand switch unit is constructed in the same manner as the onepreviously described and has stationary contacts 60 and 61 and a movableContact 62. Relay 'clips 6'3, 64 and for the relay 66 are similarlymounted to those previously described. The central switch unit alsohasKstationary contacts and 71 and a movable contact 72. This unit,however, requires no relay and hence the contact 71 is connecteddirectly to the terminal 26 by a strip 73.

The ycarrier bar 45 is provided-with insulating flanges 75\ and 76 onopposite sides of the central switch unit to serve as barriers betweenthe switch members of the respective units. The base'15 is provided witha transverse groove 77 to receive the cross bar 45 which also serves asa barrier between to connect the resilient contact members 86 i and 87.The two latter contacts are connect-y ed respectively to the controlswitch terminals 32 and 33 and the yoperation will be vexplainedhereinafter.

At the back of the base 15 is mounted an electro-magnet and armature.This magnet has a coil 90 one terminal of which is connected to thecontrol switch terminal 31 and the other terminal of the coil isconnected to the intermediate clip 59 for the left hand relay 56. Thecontrol switch terminal 33 is connected by wire 91 to the intermediateclipv 64 for the'right hand relay 66. The core of the magnet ispreferably laminated in the customary manner and secured to laterallyextending cross bars 92 which are slidably supported in the side 4plates16 and I7. The magnet core fra-me is mounted so that it may move`vertically in the slots 93 a limited amount. inated and movablevertically with respect to the magnet coil and core. The armature isconnected to the insulating cross bar or contact carrier 45 by a linkmotion which is supported by the side` plates 16 and 17. Lever plates 95and 96` of substantially bel] crank form are pivoted to the side plates17 and 16 respectively, and connected to theI lugs 80 and 81 oftheinsulating cross bar by links 97 and 978. Extending from these levers 95and 96 are connecting rods 99 and 100, the lower ends of which areconnected to The armature 94 may also be lamthe endsof the cross bar 101which carries the armature 94. The connecting rods and y links 99 and100 may be guided between lugs or projections 102 and 103 formed in theside plates 16 and 17.

IVhen the magnet is energized it lifts the armature 94 and, through themedium of the connecting links 99 and 100, tilts the lever plates 95 and96, and thus through the pull of the links 97 and 98 draws the contactcarrier 45 toward the base so as to cause the movable contacts to engagethe stationary contacts. 0n account of the inclination of the guide'slots 82 and 83 the movable contacts slide upwardly on the stationarycontacts until fully seated, thus affording a wiping contact whichinsures perfect electrical connection.

.As the contact carrier 15 is drawn backward l the inertia of the movingarmature cannot fila' apply a direct blow on the stationary parts of themechanism. The control switch may be'of any suitable construction. Oneform is illustrated diagrammatically in Fig. 12 in order to facilitate acomplete understanding of the method of operation of the invention. Inthis form the control switch has stationary contacts 105, 106 and 107and movable switch members 108 and 109 which are spring pressed in anysuitable manner. Normally the switch member 108 connects the contacts105 and 106 and the switch member 109 is normally out of contact. rl`hecontact 105 is connected to the terminal 31. The contact 106 isconnected to the terminal 32 and contact 107 is connected to theterminal 33.

The 'relay preferably employed in the switch has end caps 110 and 111adapted respectively to the upper and lower relay clips, and a centralexternal contact 112 connected to the intermediate relay clip. The endcaps are connected together by a heating element 113 arranged along sideof a bi-metallic spring arm 114v whose end normally engages part of thecontact 112.

When the apparatus is assembled and in operation the load circuit may betraced from the lett hand line terminal25, through the heater strip 113of the relay 56 to the stationary switch contact 36, thence through themovable switch member of the left hand switch unit to the stationarycontact 35 and the load terminal 28 to the load. In a similar way thecircuit may be traced from the right hand line terminal 27 through therelay 66 to the load terminal 30 and the load. r1`he intermediate linemay be traced from the terminal 26 through the strip 73, the centralswitch unit to the load terminal 29 and the load.

Ihe operation of the switch and the resultant circuits are as Jfollows:Inet us consider IP ig. 12 as showing the circuit in the oil position.The opening and closing of the switch is accomplished by the circuitswhich control the magnet. To close the switch the operator presses thebutton carried by the contact 109 when the circuit will be as follows:Line terminal 25 to elements 111, 1111, 112 (of relay 56) coil 90, 31,105, 108, 106, 109, 107, 33, 91, 112 (of relay 66) 114, 111 to terminal27.

'Ihe above operation has energized the magnet which operates to closethe switch and, in this position, a holding circuit is established bythe connecting of contacts 86 and 87 by the connector 85, so that thestarting button may be released without interrupting the magnet circuit,The circuit is now as follows: rlerminal 25 to elements 111, 114, 112,coilm90, 31, 105, 108, 106, 32, 86, 85, 87, 33, 91, 112, 114, 111 toterminal 27.

The switch is now automatically held in closed position by the magnetand, normally, can only be opened by interruptingor reducing thestrength 'of the current in the coil current.

Normally vthe circuit may be opened by `pressing the button attached tocontact 108,

which, of course, breaks the running cir-` cuit through the magnet coiland allows the armature to drop and open the switch.

In case of overload the magnet circuit will automatically be openedbetween 112 and 114 of one 0r both of the relays. In case of failure ofline voltage or abnormal drop of line voltage, the magnet will becomeweakened and unable to hold the armature against gravity and the forceof the springs and the armature will drop away from the magnet thusopening the load and magnet switches.

After the switch is once opened, it cannot normally be closed againexcept by manually pressing the button carried by contact 109. 'Ihisfeature is of great value in that vit protects the operator against theunexpected starting of the motor or other device after it-has once beenstopped.V

Although I have described the preferred form of the complete apparatusand its' method of operation, it should be understood that some of thefeatures may be employed independently of others, for instance, theshock absorbing features herein set forth are applicable to other typesof switches, so also it should be understood that invention is notlimited to the use of the particular thermostatic relay herein setforth. It should also be understood that although I broadly as they mayappear except as may be required by the state of the art or by the termsthereof.

@Certain features and combinations of the --construction disclosedherein are claimed in my Patents 1,714,085, 1,714,086, 1,783,421 and inmy pending application #432,107 filed February 28, 1930.

I claim:

1. Apparatus of the character described comprising an insulating base,line terminals arranged in one plane along one edge, load terminalsarranged in substantially the same plane along another edge, controlcircuit terminals arranged along the latter edge in another plane, pairsof oppositely disposed switch contacts connected between the respectiveline and load terminals, a carrier bar having movable switch membersadapted to bridge the contacts of the respective pairs of switchcontacts and means for moving said carrier bar connected'between theline and the load terminals.

2. Switch apparatus comprising an insulating base, line terminalsarranged in one plane along one edge, load terminals arranged insubstantially the same plane along one edge, control circuit terminalscarried by said base, pairs of oppositely disposed stationary switchcontacts positioned between tlie respective line and load terminals,

a movable carrier bar having switch members adapted to bridge thecontacts of the respective pairs of stationary contacts, auX- iliarycontacts connected to two of said control circuit terminals, a crossconnecting contact for said auxiliary cont-acts carried by said bar andmeans for moving said carrier p bar.

3. An electric switch construction including an insulating base, pairsof stationary contacts mounted on the front of said base, a

movable contact carrier at the front of said base and between thelmembers of each respective pair of stationary contacts, contact memberscarried by said contact carrier for bridging contacts for saidstationary contacts carried by said contact carrier, an electromagnetmember and an armature member therefor mounted at the rear of said base,one of said members being movable and means connecting said movablemember with said contact carrier for moving said carrier in a directionsubstantially at right angles to said base in response to the normalenergization of said electromagnet.

5. An electric switch including line terminals, load terminals andremote-switch terminals, a double break main switch having movablecontacts cbetween the line and load terminals, an electro-magnetnormally holding the main switch closed, and a double break auxiliaryswitch having a movable contact normally held in series with the magnetl by means of the magnet when the main switch is closed, spring meansfor actuating the main and auxiliary switches in opposition to themagnet and a single support for all of the foregoing elements.

BENJAMN GETCHELL.

